Technical Field
The present invention is directed to methods and systems for generating and selectively outputting two types of ink vector data usable to reproduce strokes that are hand-drawn on a position input sensor.
Description of the Related Art
Various handwriting input systems are known that allow a user to input hand-drawn (freehand) data by using a pen-shaped device. For example, electromagnetic resonance type pen-tablet input systems are known, which allow input of hand-drawn data including associated pen pressure and pen tilt data. As further examples, electrostatic type pen input systems are known, which create capacitance between a pen-shaped input device and a (tablet) sensor surface similarly to how capacitance is created between a finger and the sensor surface. Still further, input systems that output relatively simple information such as gesture information derived from a collection of determined positions of an input element are known.
Hand-drawn data or stroke (path or trace) data inputted by a pen-shaped implement is stored in a defined data type or format, which can be used (e.g., displayed) on various types of devices and applications, such as ink messaging, ink archiving and retrieval, e-mail, photo annotation, and remote video conferencing applications. Such hand-drawn data is called digital ink or ink data. Ink data is an intermediate data existing between raw data, which consists of coordinate values of user-inputted positions, and raster data, which consists of pixel data which can be directly rendered on a display as an image. As such, most ink data are vector data. Examples of different types of ink data are described in the following non-patent literature DOCUMENTS (D1) through (D5):    (D1) W3C, Recommendation 20, September 2011, “Ink Markup Language (InkML)”            (URL—http://www.w3.org/TR/2011/REC-InkML-20110920/)            (D2) Microsoft Corporation, et al., “Ink Serialized Format Specification” 2007 (URL—http//download.microsoft.com/download/0/B/E/0BE8BDD7-E5E8-422A-ABFD-4342ED7AD886/InkSerializedFormat(ISF)Specification.pdf)    (D3) W3C Working Draft 11, February 2014, “Scalable Vector Graphics (SVG) 2” (URL—http://www.w3.org/TR/SVG2/); W3C Recommendation, 16 Aug. 2011, “Scalable Vector Graphics (SVG) 1.1 (Second Edition)” (URL—http://www.w3.org/TR/2011/REC-SVG11-201110816/)    (D4) W3C, “HTMLS A vocabulary and associated APIs for HTML and XHTML W3C Recommendation 28 Oct. 2014”            (URL—http://www.w3.org/TR/htm15/)            (D5) Slate Corporation, et al., “JOT—A Specification for an Ink Storage and Interchange Format”, Version 1.0, September 1996
For example, the InkML (D1) and ISF (D2) data structures represent stroke data inputted by a pen-type device in a manner sharable amongst different applications. SVG (D3) provides a Web standard that permits drawing of a path defined by user-input control points as vector data, regardless of what type of pen device is used as an input device.
The ink data described in (D1) through (D5) all define geometric information needed to reproduce a stroke (or a trace or a path) formed by movement of a pen or a finger. Such geometric information is herein collectively called a “stroke object.” A stroke object is vector data information whose data structure includes a set of point or control point coordinates that are used collectively to reproduce a stroke (or a trace or a path) formed by movement of a pen or a finger.